1. Field of the Invention
The present invention relates to a conveying apparatus for conveying flat panels, and in particular, relates to a dual lane conveying apparatus for conveying circuit boards along parallel paths. The apparatus can be used for conveying circuit boards through a robotic pick and place machine which mounts circuit elements on the circuit boards.
2. Discussion of Related Art
Conventional machines are known wherein a conveyor belt system conveys a printed circuit board through a robotic pick and place machine. After the conveyor system moves the printed circuit board to a specific location within the pick and place machine, robotic devices place electronic elements at predetermined locations on the printed circuit board. After the electronic elements have been placed on the printed circuit board, the conveyor system conveys the printed circuit board out of the pick and place machine. A known pick and place machine is sold by Universal Instruments, Inc. of Binghamton, N.Y., under the model number 4680A GSM.
In most machines, the conveyor system receives the printed circuit board at one side of the machine, and conveys it through the machine so that it can be populated with electronic elements. After the board is populated, the conveyor system conveys the board to the opposite side of the machine, where the board is discharged. However, in some applications, it may be desirable or necessary to discharge the populated circuit board from the same side of the machine from which it entered.
In some pick and place machines, two parallel lanes extend through the pick and place machine so that two boards may be conveyed simultaneously. One such dual lane conveyor system is illustrated schematically in FIGS. 1 and 2. Each lane of the system includes two horizontally spaced, parallel conveyor belts. For example, in FIG. 1, lane 1 includes conveyor belts 14, 16 and lane 2 includes conveyor belts 10, 12.
According to the drive mechanism of the prior art conveying system, there is only one drive mechanism for moving all of the conveyor belts. In other words, if the conveyor belts 10, 12 are moved, the conveyor belts 14, 16 are also moved.
In operation, electronic elements are typically populated on the circuit boards only within zone 2, i.e., while the boards are either in P1-2 or P2-2.
However, according to this conventional system, there are some inefficiencies. For example, the spacing between conveyor belts 10, 12 and the spacing between conveyor belts 14, 16 cannot be adjusted individually. In other words, the width of lane 1 must always be equal to the width of lane 2. In addition, conveyor belts 10, 12 cannot be operated independently of conveyors belts 14, 16. Accordingly, individual control of the boards is made difficult.
Furthermore, it is not possible to move a board from lane 1 to lane 2, or vice versa. Accordingly, the prior art conveyor system is not designed to allow the boards to be conveniently discharged from the same side of the machine that they entered.
In view of some of the drawbacks of the conventional system described above, the present invention was developed to provide greater versatility to the heretofore known dual lane conveyor systems.
Advantages of the present invention include the ability to independently adjust the width of dual conveyor paths. The present invention also enables boards being conveyed to be switched from one lane to another. In addition, the present invention enables printed circuit boards to be conveniently loaded and discharged from the same side of a pick and place machine. Other advantages of the present invention will be apparent from the description that follows.
A dual lane board handling apparatus according to one aspect of the present invention includes a first zone including first and second parallel pairs of rails extending in a first direction; a second zone including third and fourth parallel pairs of rails extending in the first direction; first tracks supporting the first and second pairs of rails so that the first and second pairs of rails can move on the first tracks in a second direction perpendicular to the first direction; a drive for moving the first pair of rails on the first tracks in the second direction such that the first pair of rails can be selectively moved between a first orientation wherein it is in alignment with the fourth pair of rails and a second orientation wherein it is in alignment with the third pair of rails; a drive for moving the second pair of rails in the second direction; and belts on the first, second, third, and fourth pairs of rails for conveying boards along the rails in the first direction.
It will be appreciated that many modifications and variations of the present invention are possible in light of the teachings set forth herein, and within the purview of the appended claims without departing from the spirit and intended scope of the invention.